The proposed project is a continuation of research on the effects of marihuana (delta-9-tetrahydrocannabinol) on the reproductive system. Sexually mature female Rhesus monkeys are administered tetrahydrocannabinol (THC) and gonadotrophic hormones and sex steroids are measured. The initial phase of this study has shown that THC can alter reproductive hormones in both male and female monkeys. The proposed continuation of this research will place these changes in perspective by comparing the effects to other drugs that alter reproductive hormones; by comparing the effects produced in females with effects in males; by evaluating the effects on fertility in the female.